In 2004, A. K. Geim et al. of the University of Manchester discloses a graphene layer transferred from a highly orientated pyrolytic graphite to a silica substrate by mechanical exfoliation. The graphene layer, having a thickness of an atom, is an actual single-layered graphite. Not only overcomes the law of thermodynamics, the method also provides a way to prepare a graphene layer. However, the method has two major disadvantages: the graphene layer positions are found by human effort with a lot of time, and the graphene connected to graphite (with a quite thickness) has too small of an area to be applied in the semiconductor industry.
In recent years, other methods of preparing the graphene layer have been developed, such as pyrolysis epitaxial growing a graphene layer on silicon carbide, oxidation-reduction, chemical vapor deposition, and the likes. Those methods only form a graphene layer with a small area on a substrate of a specific material. Transferring the graphene layer from the growth substrate to another substrate needs different solvents, catalyst, or ultra high temperature pyrolysis. In other words, the transfer process is expensive and time-consuming.
Accordingly, a novel method of forming a graphene having a large area on a substrate of any material is called-for.